Circle maker apparatus



Nov. 3, 1970 GRAEF 7' 3,537,181

CIRCLE MAKER APPARATUS Filed March 3, 1969 INVENTOR. ARNOLD R. GRAEF ATTORNEY United States Patent 3,537,181 CIRCLE MAKER APPARATUS Arnold R. Graef, Wichita, Kans., assignor to Educational Tools, Inc., Wichita, Kans., a corporation of Kansas Filed Mar. 3, 1969, Ser. No. 803,593 Int. Cl. B43i 9/20 US. Cl. 33-27 4 Claims ABSTRACT OF THE DISCLOSURE This invention is a marking device including a main support body; clamp members connected through connector means to the support body; and marking means mounted Within the respective clamp members whereupon the marking means are readily adjustable relative to each other and securely anchored in a selected position and operable to inscribe circles and the like. More particularly, this invention relates to a circle maker apparatus having marking means adjustably connected to a support body structure and the marking means may be interchanged with various ones thereof for the desired function.

Numerous types of structures known to the prior art are operable to inscribe circles about a given stationary point. In fact, the conventional drawing compass is hinged at the apex and the securing of a pointed tip and a marking instrument, such as a pencil, at two different locations necessitates a relatively complex mechanism. The conventional compass structures available in the prior art are relatively economical but have numerous drawbacks as the upper connecting apex area readily loosens with no means of tightening. It is obvious that a conventional compass cannot be used if the stationary and movable points are not maintained in a predetermined spacing during its usage. Also, in the prior art the marking element is held through a hinge structure which is weak and quickly becomes inoperative. In other words, the marking element not only has to be held at the same lateral spacing during its usage but also cannot be allowed to be moved axially within the hinge structure as such would destroy the function of inscribing a circle. Also, the prior art compass structures are provided with a very sharp, long steel tip or point and such is not readily conveyed by one without injury or damage and cannot be disassembled for ease of conveyance.

In one preferred embodiment of this invention, a circle maker apparatus is provided including a main support body; a pair of clamp members secured to the support body through connector means; and marking means readily connected to the clamp members and adjustable relative to the support body. The support body is preferably of a disc structure constructed of a sheet material having a central hole adapted to receive the connector means therethrough. The clamp members each includes a support body having a centrally positioned hole to receive the connector means therethrough. One end of each clamp member is provided with a laterally extended V-shaped anchor section to receive the marking means therein for clamping against the support body. The connector means includes a bolt member inserted through the aligned holes in the clamp members and the support body having a lock washer placed against the outer head of the bolt member and a wing nut threadably mounted upon the opposite end thereof. It is noted that on connecting the clamp members to the support body, the V-shaped anchor section has its open portion facing the support body for reasons to become obvious. The marking means has various embodiments and may be a pair of wooden pencil members, each extended longitudinally within respective ones of the V-shaped anchor sections of the clamp members. Thereupon, it is seen that rotation of the wing nut upon the bolt member operates to securely clamp the pencil members against the support body in a given position. Also, the marking means may be a mechanical pencil structure, a ball point member, a steel stylus member, or a tip holder structure for holding chalk and rubber members.

One object of this invention is to provide a circle maker apparatus or compass type structure overcoming the aforementioned disadvantages of the prior art devices.

Still, one further object of this invention is to provide a circle maker apparatus having a main support body and marking means readily attachable to the support body by connector means so that the marking means may be positioned in a secure manner in any desired relationship for inscribing circles of various sizes.

Another object of this invention is to provide a circle maker apparatus readily adjustable and operable to easily secure marking means in desired axial and lateral posi tions relative to each other.

One further object of this invention is to provide a circle maker apparatus which is economical to manufacture, solidly constructed, easily adjustable, and provided with numerous safety features for ease of conveyance and usage.

Various other objects, advantages, and features of the invention will become apparent to those skilled in the art from the following discussion, taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a perspective view of a circle maker apparatus of this invention;

FIG. 2 is a fragmentary perspective view of another embodiment of the circle maker apparatus of this invention;

FIG. 3 is an exploded perspective view of the circle maker apparatus of this invention;

FIG. 4 is a perspective view of a tip holder structure of the circle maker apparatus of this invention;

FIG. 5 illustrates a stylus having a steel tip of the circle maker apparatus of this invention.

The following is a discussion and description of preferred specific embodiments of the new circle maker apparatus of this invention, such being made with reference to the drawings, whereupon the same reference numerals are used to indicate the same or similar parts and/or structure. It is to be understood that such discussion and description is not to unduly limit the scope of the invention.

Referring to the drawings in detail and particularly FIG. 1, a circle maker apparatus of this invention, indicated generally at 12, is illustrated as used to have a portion anchored in one position with the other portion rotatable thereabout to inscribe a circle indicated at 14.

The circle maker apparatus 12 includes a main support body 16; a pair of clamp members 18 and 20 positioned against opposite sides of the support body 16; connector means 22 operably engagable with the clamp members 18 and 20 to secure the same against the support body 16; and marking means 24 mounted within the clamp members 18 and 20 for reasons to become obvious. The support body 16 is of a generally circular sheet metal construction resembling a disc member and having a central connector hole 26 therethrough.

As each of the clamp members 18 and 20 are substantially identical, only one need be described in detail. The clamp member 18 is provided with a main body section 28 with an outer end formed with an arcuate curved connector section 31. The body section 28 is extended in a substantially common plane having a hole 33 therein to receive the connector means 22 as will be explained. The outer connector section 31 is of an arcuate shape preferably of a V-shape having its open portion 3 thereof placed against the support body 16 when assembled. Additionally, the clamp member 18 is provided with parallel longitudinal ridge portions 34 which add rigidity thereto.

The connector means 22 includes a bolt member 36 mountable through the aligned holes 26 and 33 respectively in the clamp members 18 and 20 and the support body 16; a lock washer member 38 to engage a head portion 39 of the bolt member 36 and the outer surface of the clamp member 18; and a wing nut member 42 threadably mounted upon the bolt member 36 and engagable with the outer surface of the other clamp member 20 for securing the same in the assembled condition.

As shown in FIG. 3 the marking means 24 includes a pair of wooden pencil members 44 and 46, eachhaving a pointed tip section 48 thereon. The pencil members 44 and 46 are readily mountable against opposite sides of the support body 16 and held thereagainst in a clamped relationship by the clamp members 18 and 20, respectively, within the V-shaped connector sections 31.

In an additional embodiment of the marking means 24, it is seen that a cap member 47 is provided readily mountable over the pointed tip section 48 of one of the pencil members 44 and 46. The cap member 47 is provided with a hardened tip portion 51 so that the same is engagable with the surface being marked, usable as the stationary point for subscribing a circle with the marker apparatus 12 of this invention.

As shown in FIG. 4, the marking means 24 also includes chalk and rubber tip holder member 53 adapted to releasably receive, for example, a chalk member 54 therein so that the circle maker apparatus 12 may be used for marking circles upon a blackboard or the like. In FIG. is shown a ball point pen member 56 of the marking means 24 whereupon the same can be readily substituted for one of the pencil members 44 and 46 as desired. Additionally, the pen member 56 can have a sharpened end portion 59 for ease in inscribing circles as will be explained.

In the use and operation of the circle maker apparatus 12 of this invention, it is obvious that a select one of the marking means 24 may be readily mounted within the clamp members 18 and 20 to anchor the same in a desired position. Assuming the use of the pencil members 44 and 46, it is seen that the same is attached by the clamp members 18 and 20 and tightened through the use of the connector means 22. In order to vary the size of the circle to be inscribed, it is obvious that the wing nut member 42 may be loosened whereupon the respective clamp members 18 and 20 and interconnected pencil members 44 and 46 may be rotated about the bolt member 36 to achieve the desired spacing therefrom for the size of circle to be inscribed. Additionally, it is obvious that the pencil members 44 and 46 may be moved axially within respective ones of the clamp members 18 and 20 to achieve the desired length. Next, it is obvious that the wing nut member 42 may be tightened on the bolt member 36 so as to achieve a clamping of the pencil members 44 and 46 between the support body 16 and the respective clamp members 18 and 20 so that the same is rigid and nonmovable. Thereupon, a circle can be inscribed with complete accuracy from this now rigid structure.

In certain instances, it may be desirable to use the cap member 47 placed over one of the pencil members 44 and 46 to achieve a firmer anchor on the surface to which the circle is being inscribed. Also, it is seen that the cap member 47 operates to cover the pointed tip section 48 of the pencil member 46 and the same may be moved to the other pencil member 44 when it becomes dull so as to have a dual source of pencil lead supply. v

Also, it is obvious that the tip holder member may be usable to hold the chalk member 54 or an eraser therewithin so as to use the apparatus 12 for drawing circles on blackboards in a conventional manner but having superior performance to those structures available in the art. Additionally, it is also noted that the marking means 12 can use the ball point pen member 56 or an overhead projector pen similar to the pencil members 44 and 46.

As shown in FIG. 2, another embodiment includes a circle maker apparatus having a pair of support bodies 16 in abutting relationship. This embodiment is desirable in that the clamp members 18 and 20 can be held in a permanent position on respective ones of the support bodies 16 with the mating wear surfaces hidden from view.

The circle maker apparatus of this invention provides a simple but rigid structure achieving continued long life due to its connecting means. Also, the circle maker apparatus of this invention is entirely safe with the use of the pencil members and other portions of the marking means, will not damage school furniture, and may easily be carried in ones pocket. More particularly, it is obvious that the marking means may be moved axially within the respective clamp members and then anchored in a given position so that the pointed end portion thereof, whether it be a ball point pen, wooden pencil, or a metal stylus, is shielded within the arcuate portion of the clamp members for carrying the same without damage to ones clothing and the like.

The new and novel circle maker apparatus of this invention has numerous desirable qualities such as being solidly constructed; durable in operation; readily adjustable to any desired setting; easily secured in the selected positions; having only the length of the marking means limiting the size of the circular arc to be inscribed; and economical to manufacture.

While the invention has been described in conjunction with preferred specific embodiments thereof, it is to be understood that this description is to illustrate the invention, which is defined by the following claims.

I claim:

1. An apparatus adapted to inscribe circles on a given surface, comprising;

(a) a main support body,

(b) marking means having a pair of marking members engageable with said support body,

(c) means for clamping said marking members against said support body, and

(d) connector means operable to releasably connect said clamping means and said marking members against said support body in a pre-selected adjusted position, said marking members having a substantial portion engaging said support body whereby frictional contact anchors same against movement, and (c) said connector means including a bolt member mounted through aligned holes in said clamp means and said suport body and a nut member threadably mounted upon one end of said bolt member adapted to secure said clamp means against said support body while holding said marking members there within. 2. An apparatus as described in claim 1, wherein; (a) said marking members being a pair of elongated pencil members having pointed tips at one end thereof and intermediate portions clamped between said support body and said clamp means, respectively, so as to be anchored against axial and lateral movement within said clamp means. 3. An apparatus as described in claim 1, wherein; (a) said support body including a pair of abutting disc members, and I (b) said clamping means including a pair of identical clamp members, each engageable with a respective outer surface of said disc members anchoring said marking means thereagainst.

4. An apparatus as described in claim 1, wherein;

(a) said support body including a pair of abutting disc members and having large areas of frictional engagement to anchor same in an adjusted position,

6 (b) said clamping means having clamp members en- 1,237,132 8/1917 Whyte.

gageable With said disc members, and 2,563,309 8/ 1951 Collins.

(c) said marking members being a pair of elongated 3,308,538 3/ 1967 Peck.

pencil members having pointed tips at one end thereof and intermediate portions clamped between 5 FOREIGN PATENTS said disc members and said clamp members, respectively, so as to be anchored against axial and lateral 2/1953 Germany movement Within said clamp members. HARRY W. H AROIAN, Primary Examiner References Cited 10 Us. CL X R. UNITED STATES PATENTS 33 149 230,876 8/1880 Kinney. 515,075 2/1894 Deats. 

